Process
OTAGO has developed a unique production process which leverages proprietary technologies for the scalable production of char-briquettes. OTAGO’s production process is built on years of iterative scientific and engineering developments. For more detailed information about the char-briquettes industry, you can now download here OTAGO’s Handbook.
Raw Materials
Biomass waste – Biomass deriving from agricultural and industrial wastes (e.g. Coconut shells, corn cobs, bamboo, palm oil kernel) are supplied from local economical activities and industries.
Charcoal residues – Charcoal dust and particles deriving from traditional charcoal production and biomass power plants (e.g. Biomass gasifiers and boilers).
Conversion to Char
Process of Pyrolisis – After crushing and drying, biomass wastes are converted into char by burning them in kilns. The biomass is decomposed by heating it to a high temperature in a kiln, with a limited supply of oxygen. This produces char (which is mostly carbon), ash and gases (mainly hydrogen, carbon monoxide and methane).
In traditional charcoal kilns, most of the gases are vented to the atmosphere. In the kilns used by OTAGO, nearly all gases are burned. This minimizes pollution and also provides heat to dry the briquettes.
Depending on the type of briquettes required, different kind of charred biomass can be combined. The finely ground char is thoroughly mixed with water and natural binder.
The resulting paste is extruded into high-density briquettes, which need to undergrow a drying process.
Innovative Drying Process
Top-lit updraft gasifier (TLUD) – Heat produced in the charring kilns is reused for the drying process. Hot air is blown in from the TLUD through a 7 meter long tunnel to racks of wet briquettes.
The racks are loaded on rails from the other end and, over 18-24 hours, move towards the hot end. This counter-flow heating and drying produces strong, uniform briquettes with a moisture content of below 8%.
